The most common refrigeration system in use in the world today employs a refrigerant that is changeable from a liquid to a vapor phase and in which the refrigerant is compressed from a vapor into a liquid, the liquid refrigerant being increased in temperature as a result of the transformation, the liquid being cooled and conveyed to an evaporator unit wherein the liquid undergoes a pressure drop and is transformed from essentially a liquid to a vapor phase, absorbing heat. The characteristics of liquids to heat upon transformation from a vapor phase to the liquid phase and to absorb heat upon transformation form a liquid to a vapor phase is utilized in refrigeration systems for refrigerators, freezers and for air conditioning buildings, automobiles, and so forth. The cooling of a closed space is achieved by passing air over a evaporator within or in communication with the closed space and heat is dissipated to the environment by passing air over a heat exchanger containing heated liquid refrigerant in a position outside of the closed space to be cooled.
A typical refrigeration system in use today employs a compressor driven by a prime mover. The most commonly used compressor employs an electric motor and in the preferred arrangement for most refrigeration systems, particularly those of a relatively small capacity such as for a refrigerator, air conditioner for a home or so forth, the electric motor and compressor are hermetically sealed as a part of the total refrigeration system. The typical refrigeration system for automobiles, large buildings, and so forth utilizes a compressor driven by a primer mover mounted externally of the closed refrigerant system.
Whether the prime mover is hermetically sealed within the system or is external of the system, a compressor employs moving parts that must be lubricated. For this reason, any refrigeration system employing a compressor typically includes lubricant mixed with the refrigerant.
The present disclosure is an improved centrifugal refrigeration unit that does not employ any type of compression system wherein one part moves against another within the confines of the closed refrigerant system. This features eliminates the need for lubricant within the hermetically sealed refrigerant circulation system.
Reference is made to U.S. Pat. No. 3,948,061 entitled "Centrifugal Refrigeration Unit", issued Apr. 6, 1976, which describes a refrigeration system in which the refrigerant circulation system does not have any parts which move against each other. The present disclosure is an improvement to the basic concept of the centrifugal refrigerant unit of U.S. Pat. No. 3,948,061 by the provision of a critical relationship between the diameter of an evaporator unit coil relative to the diameter of a condenser unit coil, both coils being rotated about a common shaft, as described in detail in the following description of the preferred embodiments.